Answer: TYPHLOSION
Explanation: Typhlosion's Kanto counterpart is obviously Charizard (third stage of the Fire starter), and their stats and height are the exact same - only their weight, types, egg groups and moves they learn set them apart.
Answer: SLUGMA
Explanation: The Pokédex says that Slugma hardens if it stays in the same place for too long, but it is a slug after all and has only 30 base Speed, so it sounds like it wouldn't be able to prevent that doom very well. But hey, apparently it can.
Answer: SWINUB
Explanation: Ah, the oh-so-annoying Swinub all over Ice Path, who all knew Endure and could waste your power points like no other Pokémon. Who wouldn't remember them?
Answer: LANTURN
Explanation: "Typing" refers to "the types it has", not it typing on the computer, of course. It is an Electric-type, but it is still a fish and lives in water, which, as the Pokémon games will not let us forget, conducts electricity. One would think that any Electric attack would make it shock itself, but in the Advance games, Lanturn has Volt Absorb, so it's in fact healed by electricity rather than hurt by it. As I said, it does explain a lot.
Answer: MUDSLAP
Explanation: Okay, this is the kind of clue that makes you go "Umm... huh?" but it really does make sense. Mud-Slap was a TM in Johto, and in fact the very first TM you received from a Gym leader. What is its number? 31. In Emerald it is a move tutor move, but not a TM, and therefore the number 31 is never associated with it in any way again.
Answer: KINGSROCK
Explanation: The second movie, The Power of One, had a Slowking in it. The "appearance" is not referring to its appearing in the movie, but the way it looked in the movie - basically, the fact it was a Slowking and not just a Slowbro. Slowking, of course, evolves from Slowpoke when traded with a King's Rock.
Answer: CIANWOODCITY
Explanation: Cianwood City has a man whose Sneasel your rival stole. He then gives you his Shuckle too, because he's so afraid of it getting stolen too. Poor guy.
Answer: EXPSHARE
Explanation: The EXP Share gives the Pokémon holding it half of the experience points from all battles, regardless of whether it fought in them or not. The EXP Share is obviously a tweaked version of the EXP All, which when carried would take half of the battle experience you gain and share it between all the Pokémon you were carrying. This, of course, does not help much if you're looking to train one particular Pokémon without having to make it battle, but you can use the EXP Share somewhat like that if you carry only two Pokémon, one to battle and one to train. The sacrifices are of course that you are forced to deposit four of your Pokémon and that your Pokémon-in-training gets only a fourth of the experience even then - the EXP All shares between all Pokémon you're carrying including the one that actually battled.
Answer: FAINTATTACK
Explanation: A number of Pokémon cards know an attack called "Feint Attack".
Answer: TOTODILE
Explanation: The "all its counterparts" should tip you off about it being a starter, and comparing all the starters will give you Totodile as the heaviest despite its shortness.
Answer: AZALEATOWN
Explanation: The service is obviously Kurt's Pokéball-making - in the Advance games you can buy special Pokéballs, but Kurt himself would probably call them mass-produced junk.
Answer: ATTRACT
Explanation: At least three people contacted me to ask if I misspelled Whitney or something. x_X The clue is not pointing to the person you'd be talking to: it's pointing to the "it" she's supposed to give to you. There are technically two "it"s, yes - the Plain Badge and the Attract TM - but obviously "PLAINBADGE" is too long.
Answer: DELIBIRD
Explanation: Delibird's signature move is Present, which was very glitchy in Gold and Silver, dealing damage depending on the two Pokémon's types rather than on Attack and Defense. Strange but true.
Answer: SUNKERN
Explanation: Sure, in base stats Sunkern is the weakest Pokémon around, but you can't compare a case like Shedinja to other Pokémon depending on base stats. At level 100 with max stats, Shedinja still has only one hit point, and that leads to it having the lowest total max stats in the game. But as I said, it's a special case.
Answer: HERACROSS
Explanation: Heracross is a Bug/Fighting type, so its Type 1 is Bug. The strongest Bug attack is Megahorn, which only Heracross could learn in G/S/C. However, later a few more Pokémon that can learn it start to pop up.
Answer: BLACKTHORNCITY
Explanation: Blackthorn is located in the mountains and is famous for having a Dragon-type Gym and the Dragon's Den near it. Dragons are of course legendary creatures.
Answer: MAHOGANYTOWN
Explanation: The Rocket hideout under Mahogany Town had six Electrode powering the radio transmitter that was making the Magikarp in the Lake of Rage evolve. Before you go to fight them, Lance says he feels bad for having to faint them all because it's no fault of the Pokémon's.
Answer: SUICUNE
Explanation: Unlike Entei who got only a movie and Raikou who got only a special episode, Suicune was both the star of Crystal and had a cameo in the fourth movie.
Answer: ANCIENTPOWER
Explanation: Well, Unown are ancient Pokémon. Ancientpower, Hidden Power... seems to fit together, doesn't it?
Answer: SHARPBEAK
Explanation: The Monica referred to is Monica of Monday, one of the siblings who give you items on certain days of the week. She gives you a Sharp Beak on Route 40 on Mondays.
Answer: ILEXFOREST
Explanation: Ilex Forest has quite a few Bug Pokémon, and the nearby Gym is of course the Azalea Town Gym run by Bugsy.